Does anyone have definitive information as to exactly when the H-4 variant entered service with the Luftwaffe ?

In various books I've been studying, this variant is shown as entering service, or at the very least replacing the H-3 variant in production, on periods ranging from '..early 1940', to 'early 1941', with at least one source being more specific, and quoting '.... from early September, 1940'.
However, various photos in these books purport to show the H-4 variant, with individual exhaust stubs, rather then the 'flame damper' type of tubular, 'collector' exhaust seen on the H-1, H-2 and H-3, at periods variously described as July and August 1940, and 'summer 1940', with units based in Northern France, and Norway.
Also, crash and interrogation reports (of downed aircrew) concerning aircraft used by KG26 (based at Stavanger, Norway) on the raids against north east England on 15th August, show the codes of the aircraft concerned, which are described as He-111H-4, as do the listings of these aircraft in three books on the subject, where at least some of the information has come from accounts by the surviving aircrew involved.
That said, at least one photo of one of the aircraft lost on that day, shows that the earlier, 'tubular' exhausts are fitted (perhaps still retained by the first production batch, before the up-grading of the engine type ?), whereas I understand that the H-4 had the individual exhausts stubs.

Staff MemberModerator

Does anyone have definitive information as to exactly when the H-4 variant entered service with the Luftwaffe ?

In various books I've been studying, this variant is shown as entering service, or at the very least replacing the H-3 variant in production, on periods ranging from '..early 1940', to 'early 1941', with at least one source being more specific, and quoting '.... from early September, 1940'.
However, various photos in these books purport to show the H-4 variant, with individual exhaust stubs, rather then the 'flame damper' type of tubular, 'collector' exhaust seen on the H-1, H-2 and H-3, at periods variously described as July and August 1940, and 'summer 1940', with units based in Northern France, and Norway.
Also, crash and interrogation reports (of downed aircrew) concerning aircraft used by KG26 (based at Stavanger, Norway) on the raids against north east England on 15th August, show the codes of the aircraft concerned, which are described as He-111H-4, as do the listings of these aircraft in three books on the subject, where at least some of the information has come from accounts by the surviving aircrew involved.
That said, at least one photo of one of the aircraft lost on that day, shows that the earlier, 'tubular' exhausts are fitted (perhaps still retained by the first production batch, before the up-grading of the engine type ?), whereas I understand that the H-4 had the individual exhausts stubs.

Any info will be gratefully received.

Click to expand...

Terry, here is what I found so far from the book Heinkel He111 by Robert Forsyth with Eddie J Creek.

One H-4 Werk number 6964 of 4/KG 26 was lost during a mission to Scapa Flow on the night of 8/9 April 1940 while one crashed at Delmenhorst on its return from the same mission. Four H-4's of 1. Staffel blew up when bombs on board apparently exploded off the coast near Sylt, while a similar fate befell another such machine of II Gruppe at Stavanger. The Gruppe also suffered the loss of another H-4 when it failed to return following operations off the Shetlands and is believed to have gone down in the see off the coast of Norway. One aircraft was 60 percent damaged following an emergency landing at Stavanger, having been damaged during combat with British fighters . These losses testify to the operational development of the He-111 H-4 by the spring of 1940.

According to Bundesarchive/RLM Data the H-4 was an Umbau (Modification/Upgrade) version and not new production. Upgrade involved external bomb carriers for heavier bombs. Possible they made them out of older H-versions which may have also involved an engien upgrade.
P-4 is also listed as Umbau, apart from different engine it may have also involved the external bomb option.
An introduction in early 40 is very likely.

Thanks Paul, that's great info, and is in line with accounts of KG 26 using the H-4 variant, earlier than September 1940, in the three books covering the subject, as well as a mention of April, 1940, in another book, which is why I found the conflicting info somewhat irritating - an 'occupational hazard' of aviation research, it would seem !
I think I might have to invest in that book (saw it recently for £35), but meanwhile, if you have any photo evidence of the H-4, especially with KG26, fitted with the individual exhausts stubs, rather than the 'tubular' exhaust, that would be great.

EDIT:- Crossing posts. Thanks Dennis, that reinforces my own thoughts on the subject, especially the dates in early 1940. Regarding the engines, all sources so far mention a change of engine to a more powerful Jumo (haven't got the type number to hand at the moment) with 'later-production' H-4 airframes, which possibly explains the differences in exhausts.

En wiki cites a book claiming late 211A had 1100PS for take-off. The 211B/D and G/H family had 1200PS although the latter was internally strengthened.
The next step, the 211F is supposed to have been introduced mid/late 41 in H-5/H-6.
Exhaust are not usable to identify an engine type - research led to many improvements here and retrofits to older aircraft.

Thanks again, Dennis and Tomo.
I agree about the exhausts - from H-4 to H-6 they are supposed to be the individual exhaust stacks, with later models reverting back to the 'flame damper' type, and modified versions of this. But photos show both types on the sub-variants mentioned, with the specific period I'm interested in (August 1940) being predominantly the tubular, 'flame damper' type.
Of course, the actual date(s) of the photographs might very well differ from the dates shown in the various photo captions, and some of these, especially in the Nowarra book, are very dubious, to say the least.
So, as I see it at the moment, it is more than likely that, in August 1940, KG26 did operate the H-4 variant, as shown in the loss reports etc, and it was possible that both types of exhausts could have been fitted, although more likely the 'flame damper' type.

Thanks Paul - that confirms the exhaust type, at least on later H-4 variants ( being in the Med, it'll be 1941 or later).
At first, I thought it was actually a H-6 variant, but it has the earlier, VDM propellors, as fitted to the H-1, H-2 and H-3, whereas the H-6 had the broad-chord VS props.
All the books i have suggest that the first H-4 variants had the Jumo 211D engines, whilst later production H-4 models had the Jumo 211-F2, and I suspect that this was related to the change of exhaust type. As I mentioned earlier, from available photo evidence, it appears that those H-4s used by KG26 in August 1940 had the tubular exhausts, and probably, therefore, the Jumo 211D engines, but at least I now know that they were in service during the period I'm interested in.
I think I need to trawl through every He-111 photo I have, taken during the period concerned (and there are lots!), to check on exhaust type, as I'll be including a 1/48th scale He-111H-4 of KG26 in my 'BoB, Hardest days' collection (along with a KG53 H-2 variant), which will total 24 to 26 models, the majority being relevant Luftwaffe subjects.

Staff MemberModerator

Thanks Paul - that confirms the exhaust type, at least on later H-4 variants ( being in the Med, it'll be 1941 or later).
At first, I thought it was actually a H-6 variant, but it has the earlier, VDM propellors, as fitted to the H-1, H-2 and H-3, whereas the H-6 had the broad-chord VS props.
All the books i have suggest that the first H-4 variants had the Jumo 211D engines, whilst later production H-4 models had the Jumo 211-F2, and I suspect that this was related to the change of exhaust type. As I mentioned earlier, from available photo evidence, it appears that those H-4s used by KG26 in August 1940 had the tubular exhausts, and probably, therefore, the Jumo 211D engines, but at least I now know that they were in service during the period I'm interested in.
I think I need to trawl through every He-111 photo I have, taken during the period concerned (and there are lots!), to check on exhaust type, as I'll be including a 1/48th scale He-111H-4 of KG26 in my 'BoB, Hardest days' collection (along with a KG53 H-2 variant), which will total 24 to 26 models, the majority being relevant Luftwaffe subjects.

Click to expand...

Your welcome Terry, I will keep looking as well but so far all the ones I have for an H-4 where med theater but that was the closest I found to see a close up of the exhaust.